Improved screw-machine



UNITED STATES PATENT 25,.

BENJAMIN A. MASON, OF NEW YORK, N. Y.

IMPROVED SCREW-MACHINE.

Specification forming part of Letters Patent No. 73,110, dated January 7, 1868.

To all vwhom it may concern:

Be it known that I, BENJAMIN A. MASON, of the city and State of New York, have invented and made a certain new and useful Improvement in Screw Machinery; and I do hereby declare the following to be a full, clear, and exact description of the said invention, reference being had to the annexed drawing, making part of this specification, wherein- Figure l is a general plan of the machine, some of the parts being in section to show the action of the cutters in forming the screw and the means for ejectiug the screw. Fig. 2 is an elevation of the machine. Figs. 3 and 4 are a side and edge view of the frame that carries the rin g-blank holder. Fig. 5 is adetached view of the blank-feeding wheel, and Fig. 6 is a rear view of the same. Fig. 7 is a section of the ring-blank holder and feeding mechanism. Fig. Sis a detached view of the cutter. Fig. 9 is a section, and Fig. l0 an end view, of the screw-driver and its actuating device 5 and Fig. 1l is an elevation of the wedge that brings the screw-driver into action.

Similar marks of reference denote the same parts.

My invention relates to machinery for cutting the thread on screws, and is particularly adapted to wood-screws with tapering or gimlet points.

Said invention consists in a ring-formed blank-carrier that is moved intermittently; and through this blank-carrier ring, and at right angles to the same, passes a second ring, that carries the cutting-tools, and is revolved gradually and continuously. rlhe cutters only l occupy a portion of this ring, and the movement of the blank carrier ring takes place during the interval when the cutters are not in contact with the screw.

I have shown in the drawing four ring-blank 'carriers and two sets of cutters on the cutterblank-holding ring and one set of cutters; or

the'number may be increased, as desired.

I will proceed to give a description of the general arrangement of the parts, and then detail the peculiarities of construction 5 and where the parts are duplicated or repeated several times around the machine, the complete description of one of said portions of the machine only will be sufficient.

In the drawing, aa are vertical frames carrying the frame b, that is between them, and is fitted with a cylindrical bed, c, for the rin g-tool carrier d; and c e are circular frames, (shown detached in Figs. 3 and 4,) that form the support in which revolve the rin gblank carriers f. Thering-tool carrier d is revolved continuously by a worm-pinion on the shaft d*r taking teeth on the edge of d, and said pinion and shaft d] receive motion from competent power applied to the shaft g, and transmitted through the pairs of miter-gears d2 d3.

In the rin g-blank carrier fare holes l l, that receive the end of a bolt, 2, when successively moved to'bring the screw-blank to the right positions. This bolt is forced back (to allow the carrier f to he moved) by means of the lever 7L, with its bar 3, acted on by the cam h (see Fig. 2) on the ring-tool carrier das that is revolved.

The progressive intermitted movement of the ring-blank carrier fis effected by a ca1n,7c, on d, that lifts the 'slide z', giving motion, by its link 4, to the bent lever 7c' and pawl-lin k 5, that takes the ratchet-wheel l on the shaft 6, and, by its gear l taking the teeth around the carrier j', gives the required extent of rotation to move another blank into position for having the thread out, as hereafter detailed.

On the shaft 6, but loose thereon, is also a blank-receiving wheel, m, around the periphery of which are notches of a size to receive the screw-blanks; and around this is a band, 7, open only at the lower part, over the receiver n. rIhe screw-blanks are to be supplied into the notches in this wheel m by any suitable means, and I move this blank-receiver, one notch each movement of the carrier j' by a cam, 8, on the tool-carrier ring d, that takes a roller and slide, o, raising the same, and the pawl 9 at the end of the arm of the slide o,

that takes the notches in m, moving the same.A

The parts are drawn back to place by a spring, 10.

sa y 73,110

As the blank-receiving wheel m is moved one notch at a time, one blank is allowed to fall into the receiver n, where it lies at the side of the pusher 11 (see Fig. 7) on the inclined side of the receiver n. This pusher' 11 is actuated at the right time by the slide 12, lever 13, and link 14 to the bent leverp, that receives motion from the slide i'. (See Fig. 7 By this arrangement the rin g-blank holder is moved as the slide i' is forced up by the cam 7c, and the pusher 11 moved back, and as the slide i comes down by the action of the spring 15, the pusher 11 forces the screw-blank into its chuck in the ring f.

The chucks receiving' the screw-blanks are formed of steel set into the ring-blank holder f, as seen in Fig. 7. Each one is formed with a countersink for the screw-head, a tubular portion for the shank, and one side thereof is removed to give access by the cutters to form the thread on the shank and point. I make use of rollers p to hold the ring f into its place within the circular bearing e.

The screw-blanks are nicked before being introduced into the blank-feed wheel m, and are rotated while the thread is cut by a series of cutters, r, on the ring d, each one being set to cut deeper than the preceding one. These cutters r are mounted in slide-rests r' in slides in said ring d, and each tool can be separately removed and sharpened by loosening its screwholder 16, and by it held when accurately adjusted to its position. Below the outer end of each slide-rest i" is a roller, ruiming outside the stationary rim s, and s is a cam-groove to direct the'cutters upon the revolving screwblank as they arrive successively intoposition.

In order 'to rotate the screw-blank while being cut, I employ the driver t, (see Figs. 9 and 10,) that passes through the shaft 17 of the pinion t', and is rotated therewith by a feather or pin, and sufficient end motion is allowed for the insertion or withdrawal of said driver. The pinion t' is rotated by the wheel u, that receives vmotion from the shaft g through the wheels 18 19 20, shaft g1, bevel-pinions g2, shaft 21, and pinion c1 on the shaft 22. The other screw-drivers in the machine are connected through the bevel-gears c2, c3, and o".

In order to move the screw-driver back and forth at the proper times, Iprovide a slide, t, with a fork, taking a collar on the screw-driver. The slide and screw-driver are drawn back by a spring, 23, and the movement of said screwdriver is controlled by the wedge tf, passing through a mortise in the slide o, and has a roller, 24, that takes against a projection upon the under side of the ring tool-holder d, to cause the screw-driver to enter the nick of the screw at the proper time, by forcing the slide along by the wedge t', or, by passing into a recess, allows the screwdriver to be withdrawn by the spring 23, when the roller 24 passes clear of this projection.

The movement of the tool-carrier d is uniform; but the speed of rotation of the screwblank may be varied, to give the desired number of threads to the inch, by changing the gear-wheel 20 and adjusting the position of the gear 19 so as to match the teeth of the wheels 1S and 20. Thereby the speed of rotation of the screw-drivers can be changed relative to the speed of movementof the cutters, thereby determining the pitch of the screwthread.

The means for delivering the screw are shown in Fig. 1, in which a slide-pusher, w, is mounted at the proper point in guides, and is actuated by the lever w1, which, in turn, is moved by the toe-piece wz, that projects from the ring tool-carrier d.

The general operations of the machine, arranged, as shown, with four rin g-blank carriers and two sets of cutters, will be readily understood to be as follows: Screw-blanksl are fed in, progressed to point of operation, and rotated, two screws being cut simultaneously on opposite sides of the machine. Then, as the cutters pass off one pair of screw-blanks, they commence to operate on the blanks of the intermediate pairs, and proceed as before.

AMeanwhile the first pair of screws are progressed on and eventually delivered, and another pair of screws are brought to place before the arrival of the cutters in the position to operate on them, as before.

This machine is adapted to'cutting any desired shape of thread or number of threads to the inch. It may also be varied by changing the chucks, so as to cut a screw-blank of a larger or smaller diameter, without any other change than that of the chucks and the adjustment of the cutters. Longer or shorter blanks may be cut by changing the cams that bring the cutters upl to form the points, these cams being separately attached, so as to be removable.

In consequence of the peculiar construction of my machine, I am enabled to cut a great variety of screw-blanks, instead of requiring separate machines, as has generally heretofore been the case.

W'hatI claim, and desire to secure by Letters Patent, is-

1. The receiver n and pusher 11, in combination with the blank-carrier f, substantially as and for the purposes set forth.

2. The ring-blank carrier f, in combination with the ring tool-holder d and cutters W', the

holder passing through the carrier, as and for the purposes set forth.

3. The arrangement of devices, as described,

for operating the pusher 11, as and for the purposes set forth.

4. The removable chucks, constructed and applied as set forth, in combination with the ring-blank carrier f, as and for the purposes specified.

5. The delivery-slide w, actuated as specified, in combination with the rin g-blank holder and ring tool-holder, as set forth.

6. A machine for cutting screws, in which the tools and their supporting-ring are moved continuously by gearing that is connected with the screw-driver by a changeable gearing, al1 arranged substantially as set forth, so that the pitch of the serew-thread may be varied, as

the blank-holder and the screw-driver, the parts being arranged and operating substantially as set forth.

speeied. Dated August 21, A. D. 1867.

7. I claim the cams k and 8, or projections BENJ. A. MASON. applied to therin g d, substantially as specified, Witnesses: in combination with the parts that supply the CHAs. H. SMITH, blank, force it into the blank-holder, and move GEO. D. WALKER. 

